Just got a fresh MOT but worsening cooling issue has become serious. :bang:Tempra 1600 SOHC injection engine.

Problem started as rapid temp gauge fluctuation, rising and falling back to 90 degrees. then ejecting coolant from overflow.



I assumed blocked radiator after I found it stone cold whilst engine was overheating. This is after I'd replaced the thermostat with an italian made BEHR (I have not tested yet but the old one tests OK with same symptoms) Just fitted a VW Scirocco radiator with no improvement and there seems to be NO hot flow through the rad. Removed water pump and it seems OK, although has recent small build up of crystallised anti freeze on housing. Was hoping for major water pump fail...

When letting water from radiator bleed most of water was stone cold with a little tepid water before it stopped from the bleeder. Absolutely cold rad pipes at front - red hot pipes at engine!

I initially thought this problem (when it was less serious) was the HG as it would overheat after a journey and eject coolant from overflow - head gasket seemed OK when I replaced it. Have not had the head skimmed.

I must admit that I re-used the original head bolts! Wish I hadn't now.

Test drive after fitting new rad - temp went over 90 after less than half a mile!!!!

At my wits end! I'm pulling the 'new' Stat tomorrow to see if that makes a difference. Hopefully not a nasty crack somewhere... probably needs head skimming?

I also have a new temp sender and will fit when I find it, although I could hear coolant boiling after the test drive... I also thought that one of the hoses might be collapsing - still a possibility as they are a bit soft.

any ideas

The engine is low mileage
so far I have replaced:

Overflow/Rad cap
Thermostat
Radiator
Checked water pump and will replace.

The fuel injection engine by nature runs hotter and the standard water pump is designed to cope with the capacity and weight of fluid from the original donor car. The extra long pipes of the X1/9 increase both.

Have a look at the flow rate of a standard water pump and compare it to other models with the same pump. The biggest capacity 128 block is the MkII Punto 1.9D but diesel doesn't run as hot.

There could be a performance option available or it could be possible to fit a smaller pulley to increase the rate of the pump similar to increasing boost of a supercharger.

Collapsed hoses sound like a good possibility, although I find it strange that the temperature went over 90 in less than half a mile! Normally the thermostat would be closed and the fluid would be recirculating around the engine, to speed up the warming. That would account for the cold rad pipes.
It seems either your thermostat is not opening, or your pump is not pumping. Did you fit a X1/9 pump to your Tempra, or kept the original? Did the Tempra have air-con?

Interesting ideas. The seller of the engine who apparently had it fitted to an X1/9 did suggest I fitted new coolant pipes... £95 a set. The car has run ok through the late summer with this engine and had a marginal overheating issue which was held off by use of the heater... This I put down to a poor radiator flow.

It has the Tempra water pump fitted which has a v belt pulley for air con as well as the 5 rib alternator belt. A two in one pulley. I wonder if the X water pump would be better???

I'm pulling off the new thermostat to check it tonight. Then will try and run without the stat to see what happens.

Get hold of some Stainless Steel dairy pipe and save money time and effort in the long run.

Right well removing the thermostat prolonged the overheat by about 5 minutes, temp went up and down in the normal range then sudden rise to max and loss of warmth from heater. The radiator got a little warm but nowhere near hot enough for the fan to come on.

Inspected hoses again and they seemed fine at idle, difficult to tell when revs are higher but there should still be some flow to the radiator? quite a bit of air was present in the radiator after initial bleeding.

So I guess it must be either a HG leak or a crack somewhere. Causing air lock in head and poor flow to radiator? It expelled about 1ltr of water over 10 mins running. Ordered HG kit with new bolts yesterday...

I tested the new thermostat and it works quickly.

LK are you referring to making up a set of cooling pipes or the under body pipes?

Think I will get the head skimmed too.

what's the best valve spring compressor for the 128 head? does a standard type one do the job ok? this kind of thing?


BTW next on the shopping list are new shocks and lower springs! the tyres are 165 55 13 and too small imo. I have them left over from my old cinq.

Its the hg/head. Need to get it skimmed this time... New bolts and gasket set at the ready. Not very expensive for this engine luckerly. Its now barely running and now has oil on the rocker cap... At least its diagnosed now...

Its had a minor issue since September, it would eject coolant after a run...

Be sure to give the ports and valves a good polish as well.

purf said:

what's the best valve spring compressor for the 128 head? does a standard type one do the job ok? this kind of thing?

BTW next on the shopping list are new shocks and lower springs! the tyres are 165 55 13 and too small imo. I have them left over from my old cinq.

Click to expand...

That's all I use. If you want nicer tyres I have a set of Phase one Uno Turbo wheels in my shed, a set of Punto Sporting 14's, a set of Strada Abarth 14's and a set of orange Punto GT wheels in my shed.

That's quite a collection of wheels!

I'm half way through removing the head again. Hoping to get it on the road again before Xmas. About to head out - its a bit cold though!

Cylinder head is at the engine re conditioners being skimmed. They advised to use a high quality gasket.

should have it back together at the weekend to enjoy the fresh mot!

My spare head is getting the studs removed ready for me to polish the ports.

http://simefiatpower.tripod.com/

Just don't ask these guys for prices if you have kids or people who are easily offended about.

Head skimmed and ready to refit today. 6 Thousandths taken off. Hopefully it'll be on the road by Monday... It was obvious the leak had been between 2&3 into the small round coolant passage. There is only about 8mm spacing between the combustion chamber and the water hole.

That's very shiny.

Its Alive!

Got it all finished at 11pm last night with time for a very short test drive which went well. All petrol stations closed and It was empty so I went for it and drove into work today and its running really well so far.

Strange thing is the temp gauge hardly moved at all and the Heater is not as hot as it has been at over the last year. I reckon the thermostat is not centered correctly? will look tomorrow.

I still have to refit the front grill and the rear access panel. Then its onto the window that has detached from its metal base (already glued with sikaflex and lasted a week as the base is rusty) and replace the front shocks. Oh yes and the .......

It was the stat which wasn't seated in the little hole after I messed with it.